Pointing devices for use with computers and other companion electronic equipment are known in the art and include trackballs, joysticks, and variations of the computer “mouse”. Typically such devices require that the user move one element (often the entire mouse) to control a cursor on a computer display, and then press or activate separate buttons to accomplish so-called “left-clicks” and “right-clicks”. Further it is common that the user must hold such devices in a fairly rigid position during use. While such tasks may not be overly challenging for many users, these tasks can be overwhelming to handicapped users. Further, such pointing devices are not absolute coordinate devices because the user cannot tell by looking at the device where on the computer display the cursor may be found.
Conventional pointing devices include at least one user-activated button, for example one button to left-click (and left double-click) and perhaps a second button to right-click. These different click functions can command different computer functions. “Left-click” and “right-click” buttons are commonly located on the upper mouse surface, and are pressed, respectively, with the second and third fingers of the user's hand.
Grasping and moving a mouse or trackball to manipulate a cursor, and then having to move a finger to click buttons may literally be impossible if the user suffers from carpal tunnel syndrome, arthritis, perhaps has a hand prosthesis, or is otherwise handicapped. A generic mouse is perhaps 2″ wide, 5″ long, and 1″ in height and has a mass of about 4 oz. Using the mouse to move a computer cursor on a display requires that the user move the entire mass of the mouse, e.g., about 4 oz. plus the weight of the user's hand, perhaps a total of 10 oz. When such movements are repeated many hours a day, many days a week, repetitive stress injury (RSI) including tendonitis, carpel tunnel syndrome, etc., can readily result. At fault is the sheer repetitiveness of user-interaction, coupled with the amount of user-generated force associated with manipulating the mass associated with the mouse.
Prior art pointing mechanisms such as digitizer tablets can provide some absolute coordinate information, but only while the digitizer stylus is in contact with the tablet surface. For instance if the stylus is contacting the upper right corner of the tablet, the user knows that the cursor will be in the upper right corner of the associated computer display. However as soon as the stylus is lifted from the digitizer tablet, the user can no longer look at the tablet and discern where on the computer display the cursor will be found. The stylus often functions as the user-interface element to manipulate the cursor, and typically can be used to emulate left mouse-clicking.
Applicant's U.S. Pat. No. 7,126,582 (2006) “Absolute Coordinate, Single User-Interface Element Pointing Device” and applicant's U.S. Pat. No. 7,538,758 (2009) described absolute coordinate pointing devices that are readily manipulated by handicapped users. Rather than manipulate a 4 oz. mouse mass with an arm and hand, these Osborn type pointing devices enable the user to use a single control element to move a lightweight film with respect to a stationary optical sensor within the device to reposition a computer cursor. The mass of the moved film typically is only about 4% or so of the mass required for movement with a conventional mouse. Manipulation is with the user's finger(s) rather than with the user's arm and hand. The greatly reduced mass required to be moved, as well as the ability to make mouse-type clicks with the single control element greatly reduces repetitive stress, and the likelihood of resultant injury to the user. Further, the Osborn pointing devices described in the '582 patent and '758 patent are absolute coordinate mechanisms. As such, a user can look at the device and know approximately where on the computer screen the cursor will be found.
What is needed is an low movable mass, absolute coordinate pointing device using a simpler (x,y) position, and preferably an (x,y,z) position, sensing unit that outputs true mouse positional data to a companion device, such as a computer, kiosk, etc. Preferably such pointing device should be scalable to enable a user to trace a given curve, perhaps a mathematical function f(t), and thus create the curve with dimensions on a computer screen, where it could be manipulated by an accompanying computer. In addition, such pointing device should be manipulable with a user's finger(s) rather than with the user's arm, hand and wrist. Preferably the device enables lifting to control element in the z-axis to implement three-dimensional functionality. The present invention provides such a pointing device.